The lens in the human eye is formed by water and fibrous proteins. The fibrous proteins are arranged in a particular manner, so that the lens is clear and light is permitted to pass through. With increasing age and due to other negative factors, fibrous proteins deteriorate and aggregate as a cluster, so that the lens becomes hardened and unclear resulting in cataracts. At this moment, it is impossible or difficult for light to pass through the lens from the cornea and project and focus on the retina. The human feels his/her vision is obscure, and cannot see any objects clearly.
Therefore, having cataracts means that the soluble proteins in the lens gradually become insoluble proteins, so the lens becomes unclear, which results in the phenomena of vision disorder, such as obscure vision, increased diopter for myopia (mild presbyopia), overlapped imaging, halation in the iris, reduced contrast vision and so on. The reasons include congenital factors, injuries, and chronic conditions, such as diabetes. The clinically most common cataracts are senile cataracts. Cataracts can be divided into nuclear cataracts, cortical cataracts, posterior subcapsular cataracts and mixed cataracts according to the sites where turbidity occurs in the lens.
Because the population is aging in developed countries and people's eyes gaze at the screen of a handheld mobile device at a short distance over long periods of time, their eyes receive high-intensity light stimulus or natural radiation, and the development of cataracts is sped up and the incidence rate of cataracts has increased globally.
Cataracts are one of the most common disorders being treated in the ophthalmology department. The patient's symptoms at the early stage include unstable vision, obscurity, diplopia, photophobia, glare at night, color change, and darkened color or distortion of the object, as well as the patient not being able to easily distinguish the brightness/darkness contrast of an object. The symptoms of late-stage cataracts are serious deterioration of vision, and blurred vision. The patient can only distinguish his fingers and the remaining light perception, and the most serious case is to cause ablepsia. Currently, there is no medicine or nutritional supplement that has been proven to effectively prevent the formation of cataracts.
Cataracts cannot be externally diagnosed by direct observation. When diagnosing cataracts, the ophthalmologist determines the shape, size and position of the opaque lens using the apparatuses, such as the slit lamp microscope, tonometer, sonicator, automatic optometry device, computer-assisted chromatic corneal topography and so on.
The current methods to prevent cataracts are to take vitamins and antioxidants, wear sun glasses to reduce the exposure to ultraviolet (UV) light, have a balanced diet and avoid smoking. However, cataract surgery is the only effective treatment.
The current clinical treatment for cataracts is to remove the unclear and opaque lens by surgery, including cataract phacoemulsification and extracapsular cataract extraction, and to implant aspherical or multi-focus artificial lens into the eye. Hyaluronan (hyaluronic acid) is used to protect the endothelium of the cornea during cataract extraction surgery. However, there is no literature to definitely indicate that hyaluronan can effectively prevent, delay or treat cataracts. Because the cost of artificial lens is not affordable by many people in the world and there are still side effects from the surgery and the risk of complications, cataracts are still the most common cause of ablepsia in humans. Therefore, undoubtedly, the development of a pharmaceutical composition and medicine for preventing, delaying or treating cataracts, or a health food for preventing or delaying cataracts has an enormous potential market.
It is therefore the Applicant's attempt to deal with the above situation encountered in the prior art.